While Sprint's tri-band LTE network is far from a secret, the company's going on an all-out marketing offensive promoting the technology, which it's now given a name: Sprint Spark. Capitalizing on the unique capabilities of its newly-purchased Clearwire spectrum, Sprint is set to roll out what will likely be the US's largest LTE network in terms of spectrum usage over the coming years. That's primarily because Sprint's Clearwire acquisition granted it a block of wireless spectrum from 2500-2600MHz, the single largest contiguous frequency lease in use by any mobile data provider in the United States.

Because Sprint controls such a large unimpeded hunk o' spectrum, this will allow it to be the first carrier in the US to outfit its towers with 8x8 radio heads (8 transmitters, 8 receivers), greatly increasing the throughput capacity of the network. Sprint will also be the first mobile network in the US to deploy a TDD LTE network, which should help keep costs down. That 2500MHz network buildout actually hasn't started outside of a few select cities, but Sprint has chosen partners in the form of Alcatel-Lucent, Nokia Solutions, and Samsung to supply the necessary equipment.

Sprint announced the first tri-band markets are Chicago, Los Angeles, Miami, New York, and Tampa - theoretically, customers in those cities with tri-band capable devices should be able to take advantage of the newly-enhanced network immediately, subject to the likely limited coverage that will be available at launch.

The problem is, though, that none of Sprint's current phones actually support tri-band yet - the first devices will launch on November 8th. Those phones are the Galaxy S4 Mini, the Galaxy Mega 6.3, the LG G2, and the HTC One Max. Sprint says "select" smartphones will receive tri-band support in OTA updates in the coming months, though we know the Galaxy Note 3 won't be one of them. And, rather importantly, three of the four devices launching on the 8th won't support Spark out of the box. The One Max, G2, and Galaxy Mega will all need to receive OTA updates at a later date in order to access Sprint's 2500MHz band. The G2's update isn't expected until 2014. Only the Galaxy S4 Mini will ship fully Spark-ready.

Sprint's promising speeds up to 50-60Mbps on the enhanced network with the carrier's current technological limitations considered, though presumably that's outdoors and in fairly ideal conditions (2500MHz signal does not have great building penetration). In the future, though, Sprint alleges there's enough capacity on the network to support speeds up to 2Gbps, and conducted an over-the-air demo [in a controlled test lab] that achieved 1Gbps. Don't get too excited about gigabit mobile data just yet, though - the network technology is still experimental, and the phones themselves aren't even close to being able to handle those kinds of speeds. It's nice to know that Sprint's thinking about the future, though.

Sprint estimates that the Spark network will cover 100 million people by the end of 2014. The Sprint Network Vision plan also indicates the carrier will start small cell site rollout next year to support the network, which should help alleviate weak spots in urban areas and dead zone pockets in rural regions. To read more about Spark, check out the links below.